In To Kill A Mockingbird, Dill lies about his father and many other things. What is his motivation? What does Dill add to the children's lives?

Like many children, Dill creates a larger-than-life father to make up for the obvious deficiences that the man exhibits. Throughout Harper Lee's novel To Kill a Mockingbird, Dill displays a knack for storytelling, and the tales about his father are among the biggest whoppers he tells. No doubt Dill feels neglected by both parents, who ship him off to his Aunt Rachel in Maycomb each summer instead of using the free time to spend with him as most parents would. Instead of admitting the awful truth to Jem and Scout, Dill creates fantastic stories that make the Finch children admire and envy him--at least some of the time.

... I asked Dill where his father was: "You ain't said anything about him."
    "I haven't got one."
    "Is he dead?"
    "No."
    "Then if he's not dead, you've got one, haven't you?"
    Dill blushed and Jem told me to hush, a sure sign that Dill had been studied and found acceptable.

Dill's fascination with Boo Radley only intensified Jem and Scout's own curiosity about Maycomb's mysterious ghoul. When he next returned, he now had a father

...taller than ours [with] a black beard (pointed) and was president of the L & N Railroad.

But by now, Jem and Scout knew him well:

    "I helped the engineer for a while," said Dill, yawning.
    "In a pig's ear you did, Dill. Hush," said Jem. "What'll we play today?"

Still later, Dill runs away from home, where Scout discovers him under her bed. Dill entertains his obviously enthralled pals with one of his greatest stories about

having been bound in chains and left to die in the basement by his new father, who disliked him...

But Scout suspected that no one could hate such a lovable fellow as Dill:

... "I said why'd you run off? Was he really hateful like you said?
    "Naw... they just wasn't interested in me."

Scout realized one big difference between Atticus and Dill's father: Atticus needed Scout. Dill believed his parents didn't need him. Their serious talk turned to Boo Radley once again, and Dill philosophized about why Boo had never run away.

"Maybe he doesn't have anywhere to run off to..."